WO2020029320A1

WO2020029320A1 - Measurement device for automatically correcting radiation detection efficiency of scintillation detector

Info

Publication number: WO2020029320A1
Application number: PCT/CN2018/101307
Authority: WO
Inventors: 谭忠强
Original assignee: 苏州速核仪器有限公司
Priority date: 2018-08-10
Filing date: 2018-08-20
Publication date: 2020-02-13
Also published as: CN109212587A

Abstract

Disclosed is a measurement device for automatically correcting the radiation detection efficiency of a scintillation detector, the measurement device comprising a verification source (2) containing trace long half-life natural radioactivity, a shielding shell (30), a drive device, a connection support (1) and a control panel, wherein the shielding shell (30) is made of a nuclear radiation prevention material, characterized in that the shielding shell (30) covers the verification source (2); the shielding shell (30) is provided with an opening (31) for the radiation of the verification source (2); the drive device is connected to the shielding shell (30); the shielding shell (30) is mounted on a detector via the connection support (1); the control panel is electrically connected to the drive device; the control panel controls the drive device, such that the opening (31) on the shielding shell (30) directly faces or faces away from the detector (4) and is open or closed; the control panel is further connected to a high-voltage circuit and an operational amplifier circuit that are inside the detector (4); and the control panel adjusts gain parameters of the high-voltage circuit and the operational amplifier circuit.

Description

Measuring device for automatically correcting radiation detection efficiency of scintillation detector

Technical field

The utility model relates to nuclear radiation detection, in particular to a measuring device for automatically correcting radiation detection efficiency of a scintillation detector.

Background technique

The nuclear radiation scintillation detector (shown in Figure 1) is mainly composed of a scintillator, a photomultiplier tube, a high-voltage power supply, and an op amp circuit; the measurement principle is that after the gamma rays enter the scintillator detector, particles and the scintillator interact to produce a weak The light is then amplified by the photomultiplier tube to generate an electrical signal, and the weak electrical signal of the photomultiplier tube is further amplified by an op amp circuit to obtain a detectable voltage pulse signal. However, on the one hand, the amplitude of the signal amplified by the photomultiplier tube due to changes in the high-voltage power supply on the other hand, and on the other hand, the detection efficiency of the scintillator detector is extremely susceptible to environmental temperature and aging. Working at its best.

At present, the commonly used method is to determine the efficiency change of the scintillation detector by detecting the number of signal pulses obtained when the radiation source of the same known activity is used. Before the device leaves the factory, a calibration source is used and then the high voltage or operational amplifier is adjusted to make the detector The number of signal pulses at the best detection efficiency; when the high voltage changes, or the detector ages, or the temperature changes after leaving the factory, the detector will deviate from the optimal detection efficiency. At this time, it needs to be readjusted to return the detector to the optimal Detect efficiency status.

The current adjustment method requires personnel to bring the calibration source to the equipment site, perform multiple measurements according to the method before leaving the factory, and then manually adjust the high-voltage or op amp circuit gain to return the detector to the best detection efficiency state; this method requires professional Technical personnel can only operate when they arrive at the equipment site. Since the equipment is installed in all parts of the country after leaving the factory, the cycle and cost of on-site adjustment operations are very high, so it is necessary to use a device that can remotely adjust automatically.

Utility model content

In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a measuring device that automatically corrects the radiation detection efficiency of the scintillation detector. The utility model is cleverly designed to realize the automatic correction adjustment of the radiation detection efficiency of the scintillation detector and save the cost of manual adjustment. .

The utility model provides a measuring device for automatically correcting the radiation detection efficiency of a scintillation detector, including a calibration source containing a trace of long half-life natural radioactivity, a shielding case, a driving device, a connecting bracket, and a control board. Made of radiating material, characterized in that: the shielding case covers the calibration source; the shielding case is provided with an opening for the calibration source to emit; the driving device and the shielding case The connection bracket mounts the shielding case on the detector; the control board is electrically connected to the driving device; the control board controls the driving device to make the shielding case open The mouth is facing or facing away from the detector, and is turned on or off; the control board is also connected to the high voltage circuit and the operational amplifier circuit in the detector; the control board adjusts the gain parameters of the high voltage circuit and the operational amplifier circuit.

Preferably, a shielding layer made of a nuclear radiation-proof material is further installed on the inner wall of the connection bracket.

Preferably, the driving device is a rotary electric machine; the rotary electric machine is mounted on the connection bracket through a bearing; the rotary electric machine is connected to the shield housing; the shield housing is a rotating member; and the rotary electric machine is driven The shielding case is rotated so that the opening is directly facing or facing away from the detector.

Preferably, a limit switch is further included, the limit switch detects a rotation angle of the rotary electric machine, and the limit switch is used for positioning the open position.

Preferably, the driving device is a rotary stepper motor controlled by codes, and the rotary stepper motor is mounted on the connection bracket through a bearing; the rotary stepper motor is connected to the shield case; the shield case It is a rotating part; the rotary stepping motor drives the shielding shell to rotate so that the opening is directly facing or facing away from the detector.

Preferably, the driving device is a power execution device installed on the opening and used to open or close the opening.

Preferably, it further includes a transmission module; the control board is connected to the detector through the transmission module; the transmission module includes a wireless transmission module: a WIFI module or a Bluetooth module or a ZigBee module and a wired transmission module: a network module or a CAN bus module Or 485 bus module.

Preferably, the control board communicates with a mobile terminal through the WIFI module or the Bluetooth module.

Compared with the prior art, the beneficial effects of the present invention are:

The utility model provides a measuring device for automatically correcting the radiation detection efficiency of a scintillation detector. The utility model includes a calibration source containing a trace amount of long half-life natural radioactivity, a shielding case, a driving device, a connection bracket and a control board. The shielding case is made of anti-nuclear radiation material. It is made, characterized in that: the shielding case covers the verification source; the shielding case is provided with an opening for the verification source to radiate; the driving device is connected to the shielding case; the connection bracket installs the shielding case on the detector; The control board is electrically connected with the driving device; the control board controls the driving device so that the opening on the shield case faces or faces the detector, opens or closes; the control board is also connected to the high-voltage circuit and the op amp circuit in the detector ; The control board adjusts the gain parameters of the high-voltage circuit and the op amp circuit.

The above description is only an overview of the technical solution of the utility model. In order to understand the technical means of the utility model more clearly and can be implemented in accordance with the contents of the description, the following describes in detail the preferred embodiments of the utility model and the accompanying drawings. Rear. The specific embodiments of the present invention are given in detail by the following embodiments and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

1 is a schematic diagram of a modular structure of a measuring device for automatically correcting a radiation detection efficiency of a scintillation detector according to the present invention;

FIG. 2 is a schematic structural diagram of a measuring device for automatically correcting a radiation detection efficiency of a scintillation detector in Embodiment 1 of the present invention; FIG.

FIG. 3 is a schematic diagram of a working principle of a measuring device for automatically correcting a radiation detection efficiency of a scintillation detector in an embodiment of the present invention.

In the figure: the connection bracket 1, the verification source 2, the shield case 30, the opening 31, the shield layer 32, the detector 4, the rotary motor 5, and the limit switch 6.

detailed description

In the following, the present invention will be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, under the premise of no conflict, the embodiments described below can be arbitrarily combined to form new implementations between technical features. example.

A measuring device for automatically correcting the radiation detection efficiency of a scintillation detector, as shown in FIGS. 1 and 2, includes a calibration source 2 containing a trace amount of long half-life natural radioactivity 2, a shielding case 30, a driving device, a connection bracket 1, and a control board. The shielding case 30 is made of a nuclear radiation-proof material, and the shielding case 30 covers the calibration source 2. The shielding case 30 is provided with an opening 31 for the calibration source 2 to emit. The driving device is connected with the shielding case 30; the connection bracket 1 mounts the shielding case 30 on the detector 4; the control board is electrically connected with the driving device; the control board Controlling the driving device to open or close the opening 31 on the shielding housing 30 directly or back to the detector 4; the control board is also connected to the high voltage circuit and the op amp circuit in the detector 4; The control board adjusts gain parameters of the high-voltage circuit and the operational amplifier circuit.

Preferably, in order to prevent the calibration source 2 from minimizing the impact on the detector 4 when no calibration is needed, the calibration source 2 is completely covered with anti-nuclear radiation when the calibration source 2 is not used, that is, the storage location, as shown in FIG. 2 It is shown that a shielding layer 32 made of an anti-nuclear radiation material is also installed on the inner wall of the connection bracket 1.

As shown in FIG. 1 and FIG. 2, the driving device is a rotary electric machine 5; the rotary electric machine 5 is mounted on the connection bracket 1 through a bearing; the rotary electric machine 5 is connected to the shield housing 30; and the shield The casing 30 is a rotating part; the rotating motor 5 drives the shielding casing 30 to rotate so that the opening 31 faces or faces the detector 4. In the first embodiment, a limit switch 6 is further included. The limit switch 6 detects a rotation angle of the rotary electric machine 5, and the limit switch 6 is used for positioning the position of the opening 31. In this embodiment, there are two configurations of the limit switch 6. The first is a single gear setting. Two limit switches 6 are evenly arranged in a range of 360 °. The rotary motor 5 is provided with a trigger gear. When the rotary motor 5 rotates 180 °, the gear is triggered. When one of the limit switches 6 is triggered, the rotary motor 5 stops. At this time, the opening 31 is facing the detector 4, and the detector 4 is corrected by the calibration source 2. After the correction is completed, The rotary motor 5 rotates 180 ° along the original direction of rotation to trigger the gear position to trigger another limit switch 6. The rotary motor 5 stops and the open 31 faces away from the detector 4; the second type is a dual unit setting. The two trigger gears are evenly set within the range of 360 °. Only one limit switch 6 is required at this time. When the rotary motor 5 rotates 180 °, one of the trigger gears triggers the limit switch 6 and the rotary motor 5 stops. The port 31 is facing the detector 4, and the detector 4 is corrected by the calibration source 2. After the correction is completed, the rotary motor 5 rotates 180 ° in the reverse direction of the original rotation direction. Another trigger position triggers the limit switch 6 and the rotary motor 5 Stop, at this time the opening 31 faces away from the detector 4.

In Embodiment 2, the driving device is a rotary stepper motor controlled by codes, and the rotary stepper motor is mounted on the connection bracket 1 through a bearing; the rotary stepper motor is connected to the shield case 30; The shielding case 30 is a rotating part; the rotary stepping motor drives the shielding case 30 to rotate so that the opening 31 faces or faces the detector 4. The rotary stepper motor is controlled by a code and is configured to rotate only 180 ° each time, the control board is triggered each time, and the rotary stepper motor rotates only half a turn to ensure that the opening 31 is facing or facing the detector 4.

In Embodiment 3, the driving device is a power executing device installed on the opening 31 and used to open or close the opening 31. In this embodiment, the driving device is configured to open or close the power execution device of the opening 31, such as a movable or rotatable opening made of nuclear radiation-proof material attached to the inner wall or the outer wall. The calibration source 2 radiates the detector 4 and the detector 4 uses the calibration source 2 for correction. After the correction is completed, the opening is closed.

Preferably, it further includes a transmission module; the control board is connected to the detector 4 through the transmission module; the transmission module includes a wireless transmission module: a WIFI module or a Bluetooth module or a ZigBee module and a wired transmission module: a network module or a CAN bus Module or 485 bus module. In Embodiment 4, the control board is connected to and communicates with a mobile terminal through the WIFI module or the Bluetooth module. It should be understood that the control board can be configured to perform automatic timing or fixed-time correction or accept only correction instructions in two ways. The first is automatic timing or fixed-time correction, that is, writing a timing or counting program in the control board, where The automatic timing correction is to record the time of the last correction and count down. When the time is zero, the automatic correction is to record the allowable number of uses of the detector 4 after the last correction, and the number of times for each use is reduced until After the usage is allowed to be zero, automatic correction will be performed; the second is to use the mobile terminal to interact with the control board to establish communication with the mobile terminal through the WIFI module or Bluetooth module. The user can send a correction command to the control board to make corrections. .

The following also provides the working principle of a measurement device for automatically correcting the radiation detection efficiency of a scintillation detector in an embodiment of the present invention, as shown in FIG. 3, including the following steps:

S11. Initialize before shipment, record the gain parameters and pulse frequency thresholds of the high voltage circuit and / or op amp circuit when the flicker detector is at the best detection efficiency; where the pulse frequency threshold is measured when the flicker detector is at the best detection efficiency Pulse frequency range

S12. Start the correction adjustment, the verification unit sends a correction instruction to the control board, and the control board starts the correction adjustment after receiving the instruction;

S21. Start the rotary motor 5 and turn the open 31 to the detector 4. The rotation angle is detected by the limit switch 6. When the limit switch 6 gives a signal, the rotary motor 5 stops rotating, and the open 31 is directly facing the detector 4.

S22. Signal measurement, the control board collects the number of signal pulses of the detector 4, for example, acquires the measurement signal frequency for 30 seconds;

S23. Determine whether the frequency of the measurement signal exceeds the pulse frequency threshold. If the frequency exceeds the threshold, go to step S24; if it does not, then no correction is required. The control board rotating motor 5 turns the opening 31 away from the detector 4 until the limit switch 6 gives a signal that the rotating motor 5 stops rotating, and the opening 31 faces away from the detector 4;

S24. Determine whether the voltage of the detection high-voltage circuit is consistent with that at the factory. If the voltage is the same, go to step S25; if not, the control board adjusts the gain parameter of the high-voltage transport circuit to make the voltage value of the high-voltage circuit close to the factory value; The gain parameters of the high-voltage transport circuit can be adjusted through the voltage regulation program integrated on the control board.

S25. The signal is measured again, and the control board collects the number of signal pulses of the scintillation detector, and acquires a new measurement signal frequency for 30 seconds.

S26. Determine whether the frequency of the new measurement signal exceeds the pulse frequency threshold. If it exceeds, the controller adjusts the gain parameter of the op amp circuit until the gain parameter of the op amp circuit is close to the factory value; if it does not exceed, the correction is completed and the control board rotates. The motor 5 turns the opening 31 away from the detector 4 until the limit switch 6 gives a signal to the rotary motor 5 to stop rotating, and the opening 31 faces away from the detector 4. Among them, the gain parameter of the op amp circuit can be adjusted by a digital potentiometer integrated on the control board.

Before step S11, the method further includes: establishing wireless communication, establishing a control board to communicate with the mobile terminal through a WIFI module or a Bluetooth module, and the verification unit is a timing trigger program or an interactive trigger program built into the mobile terminal. It should be understood that the verification unit can be configured to perform automatic timing or fixed-time correction or accept only correction instructions in two ways. The first is automatic timing or fixed-time correction, that is, the control unit uses the timing or The counting program is written, in which the automatic timing correction is to record the time of the last correction and count down. When the time is zero, the automatic correction is to record the allowable number of uses of the detector 4 after the last correction. Once the number of times is reduced until the number of permitted uses is zero, automatic correction is performed; the second is to use a mobile terminal for interaction, and the verification unit is an interactive program for the mobile terminal. The WIFI module or Bluetooth module is used to establish a connection between the control board and the mobile terminal. Communication, users can send correction instructions to control the control panel to make corrections through the mobile terminal. At the same time, based on the mobile terminal, a measurement device that can automatically correct the radiation detection efficiency of the scintillation detector is connected to the cloud, real-time communication during the adjustment process, and provide a basis for remote adjustment .

The above working principle does not make any improvement to the method of using the measuring device for automatically correcting the radiation detection efficiency of the scintillation detector of the present invention, but only on the structure of the measuring device for automatically correcting the radiation detection efficiency of the scintillation detector disclosed by the present invention. The general principle of use.

The utility model provides a measuring device for automatically correcting the radiation detection efficiency of a scintillation detector. The utility model includes a calibration source containing a trace amount of long half-life natural radioactivity, a shielding case, a driving device, a connection bracket and a control board. The shielding case is made of anti-nuclear radiation material The shielding case covers the verification source; the shielding case is provided with an opening for the verification source to emit; the driving device is connected to the shielding case; the connection bracket installs the shielding case on the detector; the control board and The driving device is electrically connected; the control board controls the driving device so that the opening on the shielding case faces or faces the detector, opens or closes; the control board is also connected to the high voltage circuit and the op amp circuit in the detector; the control board adjusts Gain parameters for high voltage circuits and op amp circuits. The utility model has a reasonable structure and an ingenious design, and realizes automatic correction and adjustment of the radiation detection efficiency of the scintillation detector, thereby saving the cost of manual adjustment.

The above are only the preferred embodiments of the utility model, and do not limit the utility model in any form; anyone of ordinary skill in the industry can smoothly implement the utility model as shown in the accompanying drawings and above; However, all equivalent changes of modifications, modifications and evolutions made by those skilled in the art using the technical content disclosed above without departing from the scope of the technical solution of the utility model are equivalent to the utility model. At the same time, any equivalent changes, modifications, and evolutions made to the above embodiments according to the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

A measuring device for automatically correcting the radiation detection efficiency of a scintillation detector, comprising a calibration source (2) containing a trace of long half-life natural radioactivity, a shielding case (30), a driving device, a connecting bracket (1), a control board, and the shielding The casing (30) is made of a nuclear radiation-proof material, and is characterized in that: the shielding casing (30) covers the calibration source (2); The opening (31) emitted by the calibration source (2); the driving device is connected to the shield case (30); the connection bracket (1) mounts the shield case (30) to a detector ( 4) up; the control board is electrically connected to the driving device; the control board controls the driving device so that the opening (31) on the shielding housing (30) is facing or facing away from the detector ( 4) Turn on or off; the control board is also connected to the high voltage circuit and the op amp circuit in the detector (4); the control board adjusts the gain parameters of the high voltage circuit and the op amp circuit.
The measuring device for automatically correcting the radiation detection efficiency of the scintillation detector according to claim 1, characterized in that the inner wall of the connection bracket (1) is further provided with a shielding layer (32) made of a nuclear radiation-proof material.
The measuring device for automatically correcting the radiation detection efficiency of a scintillation detector according to claim 1 or 2, characterized in that: the driving device is a rotary electric machine (5); the rotary electric machine (5) is mounted on the connection through a bearing On the bracket (1); the rotating electric machine (5) is connected to the shielding housing (30); the shielding housing (30) is a rotating part; the rotating electric machine (5) drives the shielding housing (30) ) Rotate so that the opening (31) faces or faces the detector (4).
The measuring device for automatically correcting the radiation detection efficiency of a scintillation detector according to claim 3, further comprising a limit switch (6), the limit switch (6) detecting a rotation angle of the rotary motor (5) The limit switch (6) is used for positioning the position of the opening (31).
The measuring device for automatically correcting the radiation detection efficiency of a scintillation detector according to claim 1 or 2, wherein the driving device is a rotary stepper motor controlled by coding, and the rotary stepper motor is mounted on the bearing through a bearing. Connected to the bracket (1); the rotary stepping motor is connected to the shielding case (30); the shielding case (30) is a rotating part; the rotating stepping motor drives the shielding case (30) The opening makes the opening (31) face or face the detector (4).
The measuring device for automatically correcting the radiation detection efficiency of a scintillation detector according to claim 1 or 2, wherein the driving device is installed on the opening (31) and used to open or close the opening ( 31) Power actuator.
The measuring device for automatically correcting the radiation detection efficiency of a scintillation detector according to claim 1, further comprising a transmission module; the control board is connected to the detector (4) through the transmission module; and the transmission module includes Wireless transmission module: WIFI module or Bluetooth module or ZigBee module and wired transmission module: network module or can bus module or 485 bus module.
The measuring device for automatically correcting the radiation detection efficiency of the scintillation detector according to claim 7, wherein the control board is connected to and communicates with a mobile terminal through the WIFI module or the Bluetooth module.